/**
 * 增加边框：copyMakeBorder(), BORDER_CONSTANT, BORDER_REPLICATE
 */

#include <opencv2/imgproc.hpp>
#include <opencv2/imgcodecs.hpp>
#include <opencv2/highgui.hpp>

using namespace cv;

//![variables]
// Declare the variables
Mat src, dst;
int top, bottom, left, right;
int borderType = BORDER_CONSTANT;
const char *window_name = "copyMakeBorder Demo";
RNG rng(12345);
//![variables]

/**
 * @function main
 */
int main(int argc, char *argv[]) {
    //![load]
    const char *imageName = argc >= 2 ? argv[1] : "lena.jpg";

    // Loads an image
    src = imread(samples::findFile(imageName), IMREAD_COLOR); // Load an image

    // Check if image is loaded fine
    if (src.empty()) {
        printf(" Error opening image\n");
        printf(" Program Arguments: [image_name -- default lena.jpg] \n");
        return -1;
    }
    //![load]

    // Brief how-to for this program
    printf("\n \t copyMakeBorder Demo: \n");
    printf("\t -------------------- \n");
    printf(" ** Press 'c' to set the border to a random constant value \n");
    printf(" ** Press 'r' to set the border to be replicated \n");
    printf(" ** Press 'ESC' to exit the program \n");

    //![create_window]
    namedWindow(window_name, WINDOW_AUTOSIZE);
    //![create_window]

    //![init_arguments]
    // Initialize arguments for the filter
    top = (int) (0.05 * src.rows);
    bottom = top;
    left = (int) (0.05 * src.cols);
    right = left;
    //![init_arguments]

    for (;;) {
        //![update_value]
        Scalar value(rng.uniform(0, 255), rng.uniform(0, 255), rng.uniform(0, 255));
        //![update_value]

        //![copymakeborder]
        copyMakeBorder(src, dst, top, bottom, left, right, borderType, value);
        //![copymakeborder]

        //![display]
        imshow(window_name, dst);
        //![display]

        //![check_keypress]
        char c = (char) waitKey(500);
        if (c == 27) { break; }
        else if (c == 'c') { borderType = BORDER_CONSTANT; }
        else if (c == 'r') { borderType = BORDER_REPLICATE; }
        //![check_keypress]
    }

    return 0;
}
